Xiaoyan Yuan1,2, Geng G Tian3, Xiuying Pei1, Xiaopeng Hu4, Ji Wu5,6. 1. Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Ningxia Medical University, Yinchuan, China. 2. Department of Emergency Medicine, Gongli Hospital, Pudong New Area, Shanghai, China. 3. Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China. 4. Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China. huxiaopeng2017@sjtu.edu.cn. 5. Key Laboratory of Fertility Preservation and Maintenance of Ministry of Education, Ningxia Medical University, Yinchuan, China. jiwu@sjtu.edu.cn. 6. Key Laboratory for the Genetics of Developmental & Neuropsychiatric Disorders (Ministry of Education), Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China. jiwu@sjtu.edu.cn.
Abstract
BACKGROUND: Autophagy is required for oogenesis and plays a critical role in response to aging caused by oxidative stress. However, there have been no reports on regulation of cytoprotective autophagy in female germline stem cells (FGSCs) in response to aging caused by oxidative stress. RESULTS: We found that Spermidine (SPD) significantly increased protein expression of autophagy markers microtubule-associated protein 1 light chain 3 beta-II (MAP1LC3B-II/LC3B-II) and sequestosome-1/p62 (SQSTM1/p62), and evoked autophagic flux in FGSCs. Moreover, SPD increased the number and viability of FGSCs in vitro. Further, we found that SPD significantly reduced basal or hydrogen peroxide (H2O2)-induced up-regulated protein expression of the aging markers, cyclin dependent kinase inhibitor 2A (p16/CDKN2A) and tumor protein 53 (p53). After knockdown of p62 in FGSCs, p16 protein levels were significant higher compared with controls. However, protein p16 levels were not significantly changed in p62 knockdown FGSCs with SPD treatment compared with without SPD. Moreover, SPD significantly changed the expression of autophagy-related genes and pathways in FGSCs, as shown by bioinformatics analysis of RNA sequencing data. Additionally, SPD significantly inhibited AKT/mTOR phosphorylation. CONCLUSIONS: SPD induces cytoprotective autophagy in FGSCs in vitro and ameliorates cellular senescence of FGSCs induced by H2O2. Furthermore, SPD can ameliorate cellular senescence of FGSCs through p62. SPD might induce autophagy in FGSCs via the PI3K/Akt pathway. Our findings could be helpful for delaying aging of female germ cells due to oxidative stress and preserving female fertility.
BACKGROUND: Autophagy is required for oogenesis and plays a critical role in response to aging caused by oxidative stress. However, there have been no reports on regulation of cytoprotective autophagy in female germline stem cells (FGSCs) in response to aging caused by oxidative stress. RESULTS: We found that Spermidine (SPD) significantly increased protein expression of autophagy markers microtubule-associated protein 1 light chain 3 beta-II (MAP1LC3B-II/LC3B-II) and sequestosome-1/p62 (SQSTM1/p62), and evoked autophagic flux in FGSCs. Moreover, SPD increased the number and viability of FGSCs in vitro. Further, we found that SPD significantly reduced basal or hydrogen peroxide (H2O2)-induced up-regulated protein expression of the aging markers, cyclin dependent kinase inhibitor 2A (p16/CDKN2A) and tumor protein 53 (p53). After knockdown of p62 in FGSCs, p16 protein levels were significant higher compared with controls. However, protein p16 levels were not significantly changed in p62 knockdown FGSCs with SPD treatment compared with without SPD. Moreover, SPD significantly changed the expression of autophagy-related genes and pathways in FGSCs, as shown by bioinformatics analysis of RNA sequencing data. Additionally, SPD significantly inhibited AKT/mTOR phosphorylation. CONCLUSIONS:SPD induces cytoprotective autophagy in FGSCs in vitro and ameliorates cellular senescence of FGSCs induced by H2O2. Furthermore, SPD can ameliorate cellular senescence of FGSCs through p62. SPD might induce autophagy in FGSCs via the PI3K/Akt pathway. Our findings could be helpful for delaying aging of female germ cells due to oxidative stress and preserving female fertility.
Authors: Laura García-Prat; Marta Martínez-Vicente; Eusebio Perdiguero; Laura Ortet; Javier Rodríguez-Ubreva; Elena Rebollo; Vanessa Ruiz-Bonilla; Susana Gutarra; Esteban Ballestar; Antonio L Serrano; Marco Sandri; Pura Muñoz-Cánoves Journal: Nature Date: 2016-01-07 Impact factor: 49.962